1. Field of the Invention
The present invention relates to a wireless access system using a space-division multiple access communication as multiple wireless communication.
2. Discussion of the Related Art
Conventionally, as disclosed in Japanese Patent No. 3926669, a wireless access system including a wireless control station and at least one wireless terminal device is known, in which the wireless control station transmits data in compliance with each of the wireless terminal devices through space-division multiple access communication. Meanwhile, data transmission to a wireless terminal device located in each directional space divided by space-division multiple access communication control is exclusively permitted, and time-division data are transmitted to the wireless control station while the wireless terminal device is permitted to transmit data by the wireless control station.
In the conventional wireless access system, data are transmitted from the wireless control station to the wireless terminal device through space-division multiple access communication in down transmission, and from the wireless terminal device to the wireless control station through time-division multiple access communication in up transmission. Therefore, in multiple access communication between the wireless control station and the wireless terminal device, interference between wireless transmission signals from the wireless terminal device is prevented, and interference waves at the wireless control station do not need removing.
However, multiple access communication between plural wireless control stations and wireless terminal devices is not considered.
In particular, a feasible technology for sharing one wireless terminal device among plural wireless control stations and controlling access is not disclosed.